The present invention relates to a device for controlling fluid delivery, for example for use in controlling ink or dampening solution delivery in a printing press.
U.S. Pat. No. 2,404,159 discloses a segmented ink transfer roller. The segments have spiral or straight ribs for transferring a given amount of ink. A change in the amount of ink transfer is achieved by exchanging the sleeve-type segments.
U.S. Pat. No. 4,896,601 discloses an ink transfer roller with recessed areas and one or more raised areas for transferring ink. The transfer rollers are driven by friction when the raised areas contact the ink fountain roller or a first distribution roller. The ink transfer roller surface speed must alternate to match whichever roll it periodically contacts.
U.S. Pat. No. 5,383,394 discloses an axially divided vibrating roller. Each segment of the vibrating roller is individually shiftable by a magnetic device.
U.S. Pat. No. 5,123,351 discloses a speed matched ductor assembly for transferring ink with first and second idler rollers movable between an ink pick up and an ink transfer position.
U.S. Pat. No. 4,402,263 discloses a segmented ink transfer control roller having individually radially adjustable ink transfer portions.
Japanese Pat. Document 2000-246873 discloses an image writing unit for writing with repellant or lipophilic ink. The image writing unit is arranged near an ink fountain roller along a shaft of the roller. In the unit, a lipophilic part and an ink repellant part are formed corresponding to a printing element rate of a press plate supplied for printing on the roller. All circumferential and axial areas of the roller are divided in a horizontal and vertical network state. An areal rate of the lipophilic part at each measure is set to increase or decrease an ink supply amount corresponding to the element rate of the press plate in an axial direction of the roller.
An object of the present invention is to provide for precise metering of fluid.
An additional or alternate object of the present invention is to provide a robust, repeatable fluid delivery device and/or method.
The present invention provides a device for controlling delivery of an amount of fluid comprising: a first rotating device having at least one peripheral first fluid transfer section; a second rotating device having at least one peripheral second fluid transfer section; and a device for setting a phase between the first and second fluid transfer sections.
By being able to set the phase between the first and second fluid transfer sections, the fluid can be precisely, robustly and repeatably provided, as the fluid transfer overlap between the first and second devices can be precisely controlled.
Preferably, the first rotating device includes a first fluid non-transfer section located in a peripheral direction from the first fluid transfer section and the second rotating device includes a second fluid non-transfer section located in a peripheral direction from the second fluid transfer section. Thus, if fluid from the first fluid transfer section coincides with the second fluid non-transfer section, this fluid is not transferred by the second rotating device.
The at least one first fluid transfer section may include two or more first fluid transfer sections spaced equidistantly in a peripheral direction, and the first rotating device may include two or more first fluid non-transfer sections between the first fluid transfer sections. The at least one second fluid transfer section may include two or more second fluid transfer sections spaced equidistantly in a peripheral direction, and the second rotating device may include two or more second fluid non-transfer ring sections between the second fluid transfer sections. The increased number of sections advantageously can reduce the phase angle change required between the first and second rotating devices to alter a specific fluid delivery.
The first fluid transfer section and the first fluid non-transfer section preferably have a same peripheral extent as do the second fluid transfer section and the second fluid non-transfer section.
Preferably, the first and/or second fluid transfer section protrudes, and the first and/or second fluid non-transfer section is recessed. The recessing advantageously provides an effective and simple means for creating the non-transfer function property of the first and/or second fluid non-transfer sections. The recess of the first and/or second fluid non-transfer section maybe deeper than a thickness of a fluid film on the first and/or second fluid transfer section, and preferably is many times that thickness.
The first and/or second fluid transfer section may define a curved rectangle or be spiral-shaped.
The first or second fluid transfer section preferably is made of an elastic deformable material, such as natural or artificial rubber, while the other fluid transfer section is made of a rigid material, such as metal, plastic or ceramic.
The first fluid transfer section may have an oleophilic surface for attracting ink and the first non-fluid transfer section may have a fluid repellant surface repelling the fluid, the fluid repellant surface being oleophopic and/or hydrophilic.
The first rotating device and second rotating device may define a gap therebetween, the gap being a timed or repeating gap, for example repeating with each rotation of the rotating devices. The gap may be formed between the first fluid transfer section and the second fluid non-transfer section, for example.
The first and second rotating devices preferably have the same peripheral speed, which may be directly related to a machine speed. A gear drive may drive the first and second rotating devices in a same or opposite rotational direction.
The first and/or second rotating device may include segments spaced axially, and the segments may be individually adjustable by the phase-setting device to control delivery of fluid over a respect axial extent of the segment.
The first and/or second rotating device preferably is a cylinder, and thus a first cylinder and a second cylinder may be provided, the first cylinder having a first diameter and the second cylinder having a second diameter. The first and second diameters have a ratio relative to each other which is an integer, for example 1 or 2.
The first and/ or second cylinder may include a shaft with the fluid transfer section having an internal control mechanism of the phase setting device for controlling a peripheral location of the first fluid transfer section. The internal control mechanism is located on the shaft, and may be axially segmented.
The internal control mechanism may include a stepper motor, a worm gear, a transfer gear and a ring gear, the ring gear being peripherally adjustable with respect to the shaft.
Instead of the cylinders, the first and/or second rotating device may include a rotating belt, for example having raised and recessed sections.
A third or more rotating devices may be located between the first and second rotating devices, so long as they have a similar diameter or peripheral extent as the first and second rotating devices or an integer thereof.
The fluid may be for example a printing ink, a dampening solution or a gloss coating.
Thus the present invention also provides an inking device for controlling delivery of an amount of ink comprising a first rotating device having at least one first peripheral ink transfer section, a second rotating device having at least one second peripheral ink transfer section, and a device for setting a phase between the first and second ink transfer sections.
Also provided is a dampening device for controlling delivery of an amount of dampening solution comprising a first rotating device having at least one first peripheral dampening solution transfer section, a second rotating device having at least one second peripheral dampening solution transfer section, and a device for setting a phase between the first and second dampening solution sections.
The present invention also provides a method for controlling delivery of an amount of fluid comprising the steps of: providing a fluid to a first rotating device having at least one peripheral first fluid transfer section; transferring at least a portion of the fluid to a second rotating device having at least one peripheral second fluid transfer section; and controlling the portion through setting of the phase between the first and second fluid transfer sections. An overlap length of the first and second fluid transfer sections may be set.